This is mostly covered above but apart from the obvious you need to
have a firm grasp on your class, at least 2 specs and just the game
in general.

We want players that can work together and achieve the goals we set
as a guild. Even though a’lot of our members log/parse around the
top of their class, playing for loot or log rankings is not what
were after. You need to be willing to put the work in mechanics
wise first and foremost